make utility.hpp available for external things that include ipmid/api.hpp

Change-Id: Iafe6827fa545d72666994bb68b5972cde4d0a1ff
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/include/Makefile.am b/include/Makefile.am
index 852b26b..55b531c 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -11,6 +11,7 @@
 	ipmid/iana.hpp \
 	ipmid/oemopenbmc.hpp \
 	ipmid/oemrouter.hpp \
+	ipmid/utility.hpp \
 	ipmid-host/cmd.hpp \
 	ipmid-host/cmd-utils.hpp